Cu alloy core bonding wire with Pd coating for semiconductor device

Abstract

A bonding wire for a semiconductor device includes a Cu alloy core material and a Pd coating layer formed on a surface thereof, and the boding wire contains one or more elements of As, Te, Sn, Sb, Bi and Se in a total amount of 0.1 to 100 ppm by mass. The bonding longevity of a ball bonded part can increase in a high-temperature and high-humidity environment, improving the bonding reliability. When the Cu alloy core material further contains one or more of Ni, Zn, Rh, In, Ir, Pt, Ga and Ge in an amount, for each, of 0.011 to 1.2% by mass, it is able to increase the reliability of a ball bonded part in a high-temperature environment of 170° C. or more. When an alloy skin layer containing Au and Pd is further formed on a surface of the Pd coating layer, wedge bondability improves.

The invention claimed is: 
     
       1. A bonding wire for a semiconductor device comprising:
 a Cu alloy core; and 
 a Pd coating layer formed on a surface of the Cu alloy core, wherein 
 the bonding wire further contains at least one of As and Te, and 
 a concentration of the at least one of As and Te in total is 0.1 ppm by mass or more and 100 ppm by mass or less relative to the entire wire. 
 
     
     
       2. The bonding wire for a semiconductor device according to  claim 1 , wherein the concentration of the at least one or more elements selected from As and Te in total is 1 ppm by mass or more and 100 ppm by mass or less relative to the entire wire. 
     
     
       3. The bonding wire for a semiconductor device according to  claim 1 , wherein a thickness of the Pd coating layer is 0.015 μm or more and 0.150 μm or less. 
     
     
       4. The bonding wire for a semiconductor device according to  claim 1 , further comprising an alloy skin layer containing Au and Pd on the Pd coating layer. 
     
     
       5. The bonding wire for a semiconductor device according to  claim 4 , wherein a thickness of the alloy skin layer containing Au and Pd is 0.0005 μm or more and 0.050 μm or less. 
     
     
       6. The bonding wire for a semiconductor device according to  claim 1 , wherein
 the bonding wire further contains at least one or more elements selected from Ni, Zn, Rh, In, Ir, Pt, Ga and Ge, and 
 a concentration of each of the elements is 0.011% by mass or more and 1.2% by mass or less relative to the entire wire. 
 
     
     
       7. The bonding wire for a semiconductor device according to  claim 1 , wherein
 the Cu alloy core contains Pd, and 
 a concentration of Pd contained in the Cu alloy core is 0.05% by mass or more and 1.2% by mass or less. 
 
     
     
       8. The bonding wire for a semiconductor device according to  claim 1 , wherein
 the bonding wire further contains at least one or more elements selected from B, P, Mg, Ca and La, and 
 a concentration of each of the elements is 1 ppm by mass or more and 100 ppm by mass or less relative to the entire wire. 
 
     
     
       9. The bonding wire for a semiconductor device according to  claim 1 , wherein, in a measurement result when measuring crystal orientations on a surface of the bonding wire, a crystal orientation <111> angled at 15 degrees or less to a longitudinal direction of the bonding wire has a proportion of 30% or more and 100% or less. 
     
     
       10. The bonding wire for a semiconductor device according to  claim 1 , wherein Cu is present at an outermost surface of the bonding wire.